other means, one that is frequently among the most effectual is to call in the assistance of others. Especially is this the case in infancy when many feats that are difficult or impossible to the child are easily performed by its parents or other adult persons, and when such persons (especially the parents) often take a delight in assisting the child in this way. That the child should receive such assistance is natural and inevitable at a certain stage of development, but it is easy to see that help thus given may constitute a source of danger to the child's development, if it is granted not only in cases of real difficulty (having regard to the child's age and capabilities) but in cases where, by the expenditure of a little additional effort, the child could attain his end unaided. If assistance is given indiscriminately the child may acquire the habit of relying upon the help of others whenever any difficulty arises; and this habit may persist throughout life, rendering the individual a relatively useless and helpless member of society, incapable of any prolonged or intensive effort[30]. Normal development, however, implies that the occasions on which assistance is required should grow fewer and fewer as ability and experience increase, so that the adult should finally be able to transact the ordinary business of life and to maintain himself, entirely by his own efforts, except of course in unusual or exceptionally difficult circumstances, or where the economic principle of the division of labour makes it desirable to call in the assistance of other persons possessing ability or training of a different nature to his own. [Sidenote: Self-determination] The other main aspect of the principle of development that we are considering, is concerned with the matter of self-guidance rather than with that of self-help. In this respect also, normal development implies a change from dependence upon others to dependence upon self. In infancy a very great part of the individual's mode of life is determined by others, and especially by his parents. Just as he is dependent upon the efforts of his parents for the necessaries of life, so is he also dependent upon their decision as to how and when he shall enjoy these necessaries. He feeds, walks, sleeps, works and plays very largely according to their pleasure. At most the nature of his play activities is left to his own discretion. Later on during the school period the authority of the parents is to some extent exchanged for that of his teachers, but it is not till a comparatively late stage of development that an individual is allowed to dispose of the bulk of his time as he himself thinks fit.